One-Pot Au@Pd Dendritic Nanoparticles as Electrocatalysts with Ethanol Oxidation Reaction

Round 1

Reviewer 1 Report

This work reports a relatively easy method to prepare Au@Pd dendrites nanoparticles for ethanol oxidation reaction (EOR). This type of architecture has resulted in interesting results and increased electrochemical activity for some reactions. However, some issues need to be addressed before the publication:

1.    The nomenclature of the samples is not homogeneous, which makes it difficult to analyze the results.

2.    The removal of the surfactant, in this case, CTAC, is not an easy task, washing only twice might not be enough (in fact, traces of foam can be seen in the images of the metallic solutions). What effects did the authors observe in this regard on the EDS analyses and the electrochemical activity?

3.    Some images do not correspond properly with figure captions.

4.    It is necessary to develop novel catalysts on the merits of durability, low cost, and high performance to replace noble metals, then, how is the development of catalysts based on noble metals justified?

5.    As this method used a simultaneous reduction of both Au and Pd metallic salts, then more specific analyses, such as HRTEM or lineal mapping are missing to confirm the formation of a Pd shell as the authors claim.

6.    There is a lack of discussion of the XPS results that may show the electronic interaction between both metals on the surface of the catalyst.

7.    Maybe the main drawback of this work is the proper use of English which makes it difficult to understand the manuscript. The authors must edit English using professional services for the work.

Therefore, I do not recommend the publication of the manuscript in its present form.

Author Response

Reviewer 2

1. The nomenclature of the samples is not homogeneous, which makes it difficult to analyze the results.

: Thank you for your kind comment. In this paper, we modified Au@Pd dendrites nanoparticles to Au@Pd DNPs.

2. 
   The removal of the surfactant, in this case, CTAC, is not an easy task, washing only twice might not be enough (in fact, traces of foam can be seen in the images of the metallic solutions). What effects did the authors observe in this regard on the EDS analyses and the electrochemical activity?

Figure S3. Before and after CTAC removal image of (a) Au₃@Pd₅ DNPs and (b) IR data of CTAC-Au₃@Pd₅ DNPs without CTAC and CTAC.

: Thank you for your kind comment. ). In order to confirm the CTAC in the sample before and after centrifugation, sample image and IR was measured to confirm that almost no CTAC remained (Figure S1). Vial images in this paper are nanoparticles before CTAC removal. We add images of nanoparticles before and after CTAC removal and IR data (Figure S3). In addition, the reference to CTAC removal method is added. (Experiment: After the parched GCE was washed by acetone, water and ethanol, the product electrochemically cleaned by 50 potential cycles at a scan rate of 50 mV s⁻¹ form −0.8 to 0.3 V versus Ag/AgCl in an alkaline electrolyte solution (KOH) to eliminate capping agents on the surfaces of catalyst.)

Ref: Lee, Y. W.; Im, M.; Hong. J. W.; Han, S. W. Dendritic ternary alloy nanocrystals for enhanced electrocatalytic oxidation reactions. ACS Appl. Mater. Interfaces, 2017, 9(50), 44018-44026.

3. Some images do not correspond properly with figure captions.

: Thank you for your kind comment. The caption of the figure was modified as follows.

Figure 1. TEM, HRTEM and HAADF−STEM image and corresponding EDS elemental mapping images of Au₃@Pd₅ DNPs (a,b,c), Au₁@Pd₁ DNPs (d,e,f) and Au₅@Pd₃ DNPs (f,g,h).

Figure 2. TEM and HR TEM images of (a) Pd DNPs, (b) Pd DNPs and TEM image of (c) Au NPs.

Figure 3. Images and UV-Vis spectra in Pd, Au₃@Pd₅, Au₁@Pd₁, Au₃@Pd₃ DNPs and Au NPs of (a, b) before reaction and (c, d) after reaction.

Figure 4. XRD data of Pd, Au₃@Pd₅, Au₁@Pd₁, Au₅@Pd₃ DNPs and Au NPs.

Figure 5. (a) CVs obtained with Pd, Au₃@Pd₅, Au₁@Pd₁, Au₃@Pd₃ DNPs and Au NPs. on GCE in 0.1M KOH were normalized with respect to the ECSA of each catalyst, respectively. Catalytic (b) mass and (c) specific activities of the different materials in the EOR with 0.1 M KOH+ 0.5 M ethanol. (Scan rate = 50 mV s⁻¹). CA curves of (d) mass activity and (e) specific activity obtained with the different catalysts in 0.1 M KOH + 0.5 M ethanol at −0.1 V vs Ag/AgCl. (f) Comparison of EOR mass and specific activities with error bars between the different catalysts.

Figure 6. XPS data of (a) Pd 3d and (b) Au 4f core levels of Pd, Au₃@Pd₅, Au₁@Pd₁, Au₃@Pd₃ DNPs and Au NPs.

Figure 7. CO stripping curves of various catalysts in 0.1 M KOH at a scan rate of 20 mV s^-1.

4. It is necessary to develop novel catalysts on the merits of durability, low cost, and high performance to replace noble metals, then, how is the development of catalysts based on noble metals justified?

: Thank you for your kind comment. Although noble metal nanoparticles are not economically efficient, they are still widely used in fuel cell or photoelectrocatalysts because they easy to control shape and durability of nanoparticles. Reference are added below to justify the important of noble metal catalysts.

1. Huang, X.; He, Z. L.; Chen, Y.; Xu, Q.; Zhu, M.; Zhai, C. Self-standing three-dimensional PdAu nanoflowers for plasma-enhanced photo-electrocatalytic methanol oxidation with a CO-free dominant mechanism. Colloid. Interface. Sci. 2022, 625, 850-858.
2. Chen, Y.; Fan, Z.; Luo, Z.; Liu, X.; Lai, Z., Li, B.; Zhang, H. High‐Yield Synthesis of Crystal‐Phase‐Heterostructured 4H/fcc Au@ Pd Core–Shell Nanorods for Electrocatalytic Ethanol Oxidation.  Mater.2017, 29(36), 1701331.
3. Liang, W.; Wang, Y.; Zhao, L.; Guo, W.; Li, D.; Qin, W.; Jiang, L. 3D Anisotropic Au@ Pt–Pd Hemispherical Nanostructures as Efficient Electrocatalysts for Methanol, Ethanol, and Formic Acid Oxidation Reaction.  Mater.2021, 33(30), 2100713.
4. Yu, J.; Jin, H.; Wang, Q.; Wei, X.; Chen, H.; Wang, Y. Coalescence of Au–Pd Nanoropes and their Application as Enhanced Electrocatalysts for the Oxygen Reduction Reaction. Small, 2022, 18(44), 2203458.
5. As this method used a simultaneous reduction of both Au and Pd metallic salts, then more specific analyses, such as HRTEM or lineal mapping are missing to confirm the formation of a Pd shell as the authors claim.

: Thank you for your kind comment. The lineal mapping of Au3@Pd7 DNPs is add as data. In addition, EDS mapping in figure 1 and UV-vis spectra in figure2 are evidence of the core-shell structure. The AuPd alloy nanoparticles have no absorbance around 500 nm, and the data by EDS mapping of TEM can confirm that Au and Pd completely overlap with reference below. Figure S2. (a) HAADF-STEM image and (b) cross-sectional compositional line profiles of Au₃@Pd₅ DNPs.

1. Lee, Y. W.; Kim, M.; Kim, Y.; Kang, S. W.; Lee, J. H.; Han, S. W. Synthesis and electrocatalytic activity of Au− Pd alloy nanodendrites for ethanol oxidation. J. Phys. Chem. 2010, 114(17), 7689-7693.
2. Lee, Y. W.; Kim, M.; Kang, S. W.; Han, S. W. Polyhedral bimetallic alloy nanocrystals exclusively bound by {110} facets: Au–Pd rhombic dodecahedra.  Chem. Int. Ed. 2011, 50(15), 3466-3470.
3. Metin, Ö.; Sun, X.; Sun, S. Monodisperse gold–palladium alloy nanoparticles and their composition-controlled catalysis in formic acid dehydrogenation under mild conditions. Nanoscale, 2013, 5(3), 910-912.
4. There is a lack of discussion of the XPS results that may show the electronic interaction between both metals on the surface of the catalyst.

: Thank you for your kind comment.  

7. Maybe the main drawback of this work is the proper use of English which makes it difficult to understand the manuscript. The authors must edit English using professional services for the work.

: Thank you for your kind comment. The content of this paper has been revised by adding additional details.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Choi et al. report on the “One-pot Au@Pd Dendritic Nanoparticles as Electrocatalysts with Ethanol Oxidation Reaction.” The content of the work is interesting, but the manuscript cannot be published in the present form due to the following issues:

1.      Since the manuscript deals with the noble metal involving Au, Pd as a catalyst following manuscript should be added in the introduction:- Journal of The Electrochemical Society, 166 (5) H3112-H3118 (2019)

2.      Since the authors have used CTAC, so FTIR is required for the confirmation of that no organic component is left with the final products

3.      SAED pattern is absent in Figure 1

4.      In figure 3 (d) why after the reaction that samples Au5@Pd3 show the hump around 500 to 600 nm

5.      In Figure 5 (b) and (c) the samples containing more Au, there is no shoulder peak around 0.3 V vs Ag/AgCl. Explain

6.      The Error bars are absent in Figure 5 (f)

 

7.      In Figure 7 (b) the small peak is absent around -0.120 V for the sample Au3@Pd5.

Author Response

Reviewer 3

1. Since the manuscript deals with the noble metal involving Au, Pd as a catalyst following manuscript should be added in the introduction:- Journal of The Electrochemical Society, 166 (5) H3112-H3118 (2019)

: Thank you for your kind comment. Reference suggested by reviewer have been added to this paper.

Quang, N. D.; Majumder, S.; Kim, C.; Kim, D. Incorporation of an Au-rGO layer to enhance the photocatalytic application of optimized CdS thin film. J. Electrochem. Soc. 2019, 166(5), H3112.

2. 
   Since the authors have used CTAC, so FTIR is required for the confirmation of that no organic component is left with the final products

Figure S3. Before and after CTAC removal image of (a) Au₃@Pd₅ DNPs and (b) IR data of CTAC-Au3@Pd5 DNPs

: Thank you for your kind comment. Vial images in this paper are nanoparticles before CTAC removal. We add images of nanoparticles before and after CTAC removal as data. In addition, the reference to CTAC removal method is added. (Experiment: After the parched GCE was washed by acetone, water and ethanol, the product electrochemically cleaned by 50 potential cycles at a scan rate of 50 mV s⁻¹ form −0.8 to 0.3 V versus Ag/AgCl in an alkaline electrolyte solution (KOH) to eliminate capping agents on the surfaces of catalyst.)

Ref: Lee, Y. W.; Im, M.; Hong. J. W.; Han, S. W. Dendritic ternary alloy nanocrystals for enhanced electrocatalytic oxidation reactions. ACS Appl. Mater. Interfaces, 2017, 9(50), 44018-44026. 

3. SAED pattern is absent in Figure 1.

: Thank you for your kind comment. We confirmed the crystallinity using FFT pattern instead of the SEAD pattern. The corresponding fast Fourier transform (FFT) pattern further corroborates the single crystallinity of the Au₃@Pd₅, Au₁@Pd₁ and Au₃@Pd₃ DNPs. We add this data to supporting information.

Figure S1. FFT pattern images of (a) Au₃@Pd₅, (b) Au₁@Pd₁ and (c) Au₃@Pd₃ DNPs

4. In figure 3 (d) why after the reaction that samples Au5@Pd3 show the hump around 500 to 600 nm.

: Thank you for your kind comment. Au@Pd nanoparticles show plasmonic property of Au nanoparticles. In figure 3, the absorbance at 500-600 nm is proof that core is Au NPs, and the absorbance of Au5@Pd3 DNPs increased because the Au ratio increased. This paper add the references reported below.

1. Chiu, C. Y.; Yang, M. Y.; Lin, F. C.; Huang, J. S.; Huang, M. H. Facile synthesis of Au–Pd core–shell nanocrystals with systematic shape evolution and tunable size for plasmonic property examination. Nanoscale, 2014, 6(13), 7656-7665.
2. Ferrer, D.; Torres-Castro, A.; Gao, X.; Sepulveda-Guzman, S.; Ortiz-Mendez, U.; Jose-Yacaman, M. Three-layer core/shell structure in Au− Pd bimetallic nanoparticles. Nano Lett. 2007, 7(6), 1701-1705.
3. In Figure 5 (b) and (c) the samples containing more Au, there is no shoulder peak around 0.3 V vs Ag/AgCl.

: Thank you for your kind comment. Although the core-shell nanoparticles are bimetallic, since they react only on the surface of catalysts in the electrochemical reaction, Au@Pd DNPs in elelctrochemical recation is caused by Pd. However, core-shell NPs are being studied because the potential energy of the surface of the shell differs depending on the core. Reference reported in this paper are add below.

1. Zhou, X., Ma, Y., Ge, Y., Zhu, S., Cui, Y., Chen, B.; Zhang, H. Preparation of Au@ Pd Core–Shell Nanorods with fcc-2H-fcc Heterophase for Highly Efficient Electrocatalytic Alcohol Oxidation.  Am. Chem. Soc.2021, 144(1), 547-555.
2. Wu, C.; Li, H.; He, H.; Song, Y.; Bi, C.; Du, W.; Xia, H. Compressive strain in core–shell Au–Pd nanoparticles introduced by lateral confinement of deformation twinnings to enhance the oxidation reduction reaction performance. ACS appl. Mater. interfaces 2019, 11(50), 46902-46911.
3. Zhang, H.; Luo, Y.; Chen, D.; Liu, H., Cui, P.; Yang, J. Ionic liquid-derived core–shell gold@ palladium nanoparticles with tiny sizes for highly efficient electrooxidation of ethanol. Green Energy & Environment, 2021, 6(2), 229-235.
4. The Error bars are absent in Figure 5 (f)

 : Thank you for your kind comment. We modified Figure 5(f) by adding error bars.

 

Figure 5. (a) CVs obtained with Pd, Au₃@Pd₅, Au₁@Pd₁, Au₃@Pd₃ DNPs and Au NPs. on GCE in 0.1M KOH were normalized with respect to the ECSA of each catalyst, respectively. Catalytic (b) mass and (c) specific activities of the different materials in the EOR with 0.1 M KOH+ 0.5 M ethanol. (Scan rate = 50 mV s⁻¹). CA curves of (d) mass activity and (e) specific activity obtained with the different catalysts in 0.1 M KOH + 0.5 M ethanol at −0.1 V vs Ag/AgCl. (f) Comparison of EOR mass and specific activities with error bars between the different catalysts.

 

7. In Figure 7 (b) the small peak is absent around -0.120 V for the sample Au3@Pd5.

 : Thank you for your kind comment. In CO stripping curve, there are a weak peak in figure 7b. and compared to other catalysts, the Au₃@Pd₇ DNPs show that CO is easily removed and peak intensity is weak.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear editor,

 

The manuscript “One-pot Au@Pd Dendritic Nanoparticles as Electrocatalysts with Ethanol Oxidation Reaction” is well written and shows great results in EOR. There are some comments to the authors for improving the work for further publication.

 

Abstract

1) Should be a summary of the whole text showing the importance of bimetallic nanostructures and why a new catalyst is needed, the methodology fundamentals, the results and conclusions. It must be improved.

2) The keywords must be different from the title. It helps to get the work with more visibility.

Introduction

3) The introduction section is poor. It must be improved with more sentences with the importance of EOR catalysts. A state-of-art is required.

4) The authors are encouraging to show more references about the use of Au@Pd nanoparticles and your counter-parts to show the advantages and applicability of using Au@Pd bimetallic nanoparticles in several knowledge areas, such as: 10.1016/j.snb.2021.130907; 10.1016/j.jece.2021.105821; 10.1038/s41586-022-04397-7.

Materials and Methods

5) In line 50: H2O must be in subscript.

6) Why the authors don’t mixture Nafion with the catalyst rather than drop after catalyst is onto electrode surface?

Results and discussion and conclusion

7) In line 101 the authors started to describe some peaks in some spectrum that was not mentioned in the text. Verify this.

8) Figures cannot appear one after the other. They appear as the texts with the results and due discussions are introduced.

9) The authors must explain what are the due assignments of the bands in Figure 3c. (charge-transfer metal ligand? For both precursor complexes)

10) In Fig 5a, the authors must attribute what are the oxidation process in each peak in all the voltammograms. (Continue the explanations after the lines 162).

11) Why the authors didn’t show the survey XPS spectra?

12) The authors must improve the discussion of Fig 7. It is poor scientifically.

13) The authors must take a table of bimetallic electrocatalysts to compare the efficiency of the proposed catalyst with the literature.

14) Conclusions must be improved.

Author Response

Reviewer 4

1) Should be a summary of the whole text showing the importance of bimetallic nanostructures and why a new catalyst is needed, the methodology fundamentals, the results and conclusions. It must be improved.

: Thank you for your kind comment. We have revised the conclusion by adding the contents, and presented below.

“In summary, in order to the stability of Pd, we synthesized bimetal NPs by adding Au with excellent durability. In addition, we have developed a facile one-pot synthesis of Au@Pd DNPs in aqua solution that can be easily synthesized in an aqua solution rather than existing method of core-shell by a step reaction using seed with small nanoparticles.”

2) The keywords must be different from the title. It helps to get the work with more visibility.

: Thank you for your kind comment. We modified keywords with CO stripping curve; One-pot synthesis strategy and catalysts of Electrocatalytic performance.

3) The introduction section is poor. It must be improved with more sentences with the importance of EOR catalysts. A state-of-art is required.

: Thank you for your kind comment. The advantage of the EOR have been added to the introduction of this paper.

In particular, the fuel cells have rapidly increased in fuel cell development using hydrogen, ethylene glycol, methanol and ethanol as an alkaline electrolyte for decades. In addition, the advantage of direct ethanol fuel cell (DEFC) are that it can produce ethanol to large amount, it is renewable energy resource, it is low toxicity, and this development is increasing due to green energy. The oxidation of ethanol involves twelve electrons per molecule resulting in higher energy density compare to methanol [12-14]. It has been reported noble metal NPs are highly activity as catalysts for ethanol oxidation reaction. Although noble metal NPs are not economically efficient, they are still widely used in fuel cell or photoelectroncatalysts because they easy to control shape and durability of NPs [15-18].

4) The authors are encouraging to show more references about the use of Au@Pd nanoparticles and your counter-parts to show the advantages and applicability of using Au@Pd bimetallic nanoparticles in several knowledge areas, such as: 10.1016/j.snb.2021.130907; 10.1016/j.jece.2021.105821; 10.1038/s41586-022-04397-7.

: Thank you for your kind comment. In this paper, we have added an additional description and reference of Au@Pd nanoaprticles.

1. Lu, Y.; Zhang, J.; Wang, W.; Fan, Y.; Liu, C.; Zhou, J.; Ruan, S. Au-Pd modified SnS2 nanosheets for conductometric detection of xylene gas.  Actuators B. Chem.2022, 351, 130907.
2. de Barros, M. R.; Winiarski, J. P.; Elias, W. C.; de Campos, C. E. M.; Jost, C. L. Au-on-Pd bimetallic nanoparticles applied to the voltammetric determination and monitoring of 4-nitroaniline in environmental samples.  Environ. Chem. Eng.2021, 105821.
3. Huang, X.; Akdim, O.; Douthwaite, M.; Wang, K.; Zhao, L.; Lewis, R. J.; Hutchings, G. J. Au–Pd separation enhances bimetallic catalysis of alcohol oxidation. Nature, 2022, 603(7900), 271-275.

5) In line 50: H2O must be in subscript.

: Thank you for your kind comment. We modified H2O to H₂O in the experiment method. “Gold (Ⅲ) choride hydrate (HAuCl₄ xH₂O; 99%), Potassium (Ⅱ) tetra chloride, (K₂PdCl₄; 98%), CTAC (Aldrich, solution in water, 25 wt %) were purchased from Aldrich. Other chemicals, unless specified, were reagent grade, and deionized water with a resistivity of greater than 18.0 MΩ·cm was used in the preparation of aqueous solutions.”

6) Why the authors don’t mixture Nafion with the catalyst rather than drop after catalyst is onto electrode surface?

: Thank you for your kind comment. The reason for adding nafion during slurry preparation is that in general, the direct ethanol fuel cell (DEFC) has a low operating temperature, high power density, a clear phase separation between the hydrophilic and hydrophobic regions, and the polymer is flexible to form an ion aggregate well. When nafion was mixed to nanoparticles, the dispersion of catalysts was low. Therefore, the nafion was drop on catalysts after drying samples.

7) In line 101 the authors started to describe some peaks in some spectrum that was not mentioned in the text. Verify this.

: Thank you for your kind comment. We have added reference to this paper.

Lee, S.; Cho, H.; Kim, H. J.; Hong, J. W.; Lee, Y. W. Shape-and Size-Controlled Palladium Nanocrystals and Their Electrocatalytic Properties in the Oxidation of Ethanol. Materials, 2021, 14(11), 2970.

8) Figures cannot appear one after the other. They appear as the texts with the results and due discussions are introduced.

: Thank you for your kind comment. The layout of figures modified in this paper. (Revision of this paper)

9) The authors must explain what are the due assignments of the bands in Figure 3c.

: Thank you for your kind comment. We have added reference to this paper. Also “Figure 3a,c show the images before and absence of peak at 310 and 407 nm correspond to unreduced Au (Ⅲ) and Pd (Ⅱ) + CTAC complex,”

Lee, Y. W.; Kim, M.; Kim, Z. H.; Han, S. W. One-step synthesis of Au@ Pd core− shell nanooctahedron. J. Am. Chem. Soc. 2009,131(47), 17036-17037.

10) In Fig 5a, the authors must attribute what are the oxidation process in each peak in all the voltammograms. (Continue the explanations after the lines 162).

: Thank you for your kind comment. Figure 5a confirm that shell of Au@Pd DNPs is actually composed of Pd, similar in -0.3 V to the reduction peak position of Pd oxide toward Pd DNPs. Notably, Figure 5b and 5c indicate specific and mass anodic peaks in the forward and reverse sweeps for the five samples during the ethanol oxidation.

11) Why the authors didn’t show the survey XPS spectra?

: Thank you for your kind comment. In this paper, we have added an additional description of XPS.

The high resolution Au 4f and Pd 3d spectra of all catalysts show two peaks assigned to 4f_7/2 and 4f_5/2 in Au, and Pd 3d_5/2 and 3d_3/2 in Pd, respectively (Figure 6). The two peaks of the Au@Pd catalysts are shifted to lower binding energies than those of pure Au NPs, indicating electron transfer from contacted Pd to Au. The shift was induced by the higher electronegativity of Au with 2.54 than Pd with 2.2. The two peaks in Figure 6a represent Pd 3d_5/2 and 3d_3/2 trajectories in the high resolution spectrum. The high resolution Pd 3d spectra appeared clearly at higher binding energy for the catalysts of Au@Pd DNPs than for the Pd DNPs (Figure 6a). The Au 4f and 3d binding energy of Au@Pd DNPs were lower or higher than Au NPs and Pd DNPs, respectively. As prepared Au@Pd DNPs and , Pd DNPs and Au NPs suggest than both migration of Au core atom and dissolution of Pd shell atoms induce additional lattice tensile strain in formed Au and Pd. Therefore, the catalytic performance of Au@Pd DNPs in EOR was improved compared to Pd DNPs and Au NPs.

12) The authors must improve the discussion of Fig 7. It is poor scientifically.

: Thank you for your kind comment. We added the contents to this paper as follows

We were subjected to CO stripping voltammetry with various catalysts in 0.1 M KOH solution. We adsorbed CO on the metal surface while bubbling it in a 1 atm electrolyte solution for 20 min. The electrolyte solution was purged with high purity N₂ to repace CO in the solution and adsorb CO on the Pd surface. The scan rate 20 mVs-1 was performed between -0.8 and 0.3 V to induce CO oxidation of the catalysts. The first voltammetry scan was recorded after CO removal to confirm removal of CO from Pd.  

13) The authors must take a table of bimetallic electrocatalysts to compare the efficiency of the proposed catalyst with the literature.

: Thank you for your kind comment. The table1 comparing Au3@Pd7 DNPs with other catlaysts is added

Table 1.

Catalyst	Electrolyte condition	Mass activity (mAmg-1)	Scan rate (mVs-1)	Ref.
Au@Pd DNPs	0.1 M KOH + 0.5 M ethanol	2268	50	This Work
Nanowire PdPt	0.5 M NaOH + 1 M ethanol	950	50	1
Pd-Ni-P NPs	0.1 M KOH 0.5 M ethanol	110	10	2
AuPd@Pd CSNF	0.5 M KOH 0.5 M ethanol	1300	50	3
AuPd bimetal NPs	1 M NaOH + 0.6M ethanol	1065	50	4
AuPd nanowire	1 M KOH + 0.1 M ethanol	1400	20	5
Au-Island-Covered Pd Nanotubes	1 M KOH + 1 M ethanol	966	50	6
Au@Pd CNBs	0.1 M KOH + 0.5 M ethanol	800	50	7
Au@FePd nanoparticles	1 M KOH + 1 M ethanol	1350	50	8
Se-supported Au/Pd NPs	1 M KOH + 1 M ethanol	1200	50	9
AuPd CNT	1 M KOH + 1 M ethanol	1100	50	10

 

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14) Conclusions must be improved.

: Thank you for your kind comment. We have revised the conclusion by adding the contents, and presented below.

“In summary, in order to the stability of Pd, we synthesized bimetal NPs by adding Au with excellent durability. In addition, we have developed a facile one-pot synthesis of Au@Pd DNPs in aqua solution that can be easily synthesized in an aqua solution rather than existing method of core-shell by a step reaction using seed with small nanoparticles.”

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The article is of interest since the synthesis methodology of this type of nanoparticles was significantly simplified, for which reason I recommend its publication with minor corrections.

Reviewer 2 Report

Since the authors have addressed all the comments and suggestions from the referees, I recommend the publication of the manuscript in its present.

Reviewer 3 Report

The authors have been improved the manuscript with the suggestions. Therefore, I recommend the publication of manucript in Catalysts.